1. Field of Invention
The present invention relates to a tabletop for foldable tables, and more particularly to a stackable tabletop having geometrically conditioned contours that enable the tabletop to stack on another of the same kind with substantial retaining force therebetween.
2. Description of Related Arts
The transportable utility renders the fordable tables being useful for various kinds of activities, such as annual meetings in school's hall, church gathering, beverage reception in a particular university's podium, exhibitions, and the likes. Very often, these participant-intensive activities take place in multi-function rooms or designated areas in which the related furniture and equipments are temporary set up. After the functions, all the furniture and equipment will be cleared from the multi-function rooms or the designated areas and neatly stored to, say, other storage room for further uses, and the multi-function rooms or the designated areas will be made over for other purposes.
Fordable tables are usually utilized by function's host to support or retain the necessary equipment in that they are foldable and portable so that they can be easily set up when necessary, and removed after the functions ended. A conventional foldable table usually comprises a tabletop having a utilizing portion on top of which beverage, food, documents and other miscellaneous items may be placed, to whose bottom surface at least a pair of leg frames pivotally attached to provide structural support in a foldable manner.
Regarding to such conventional foldable table, some deep-seated drawbacks can be found. First, foldable tables are hard to stack up. Foldable tables are prevalent because of their flexibility. When needed, they can be unfolded for retaining and supporting a variety of objects. When they are not needed, they can be folded up into a relatively compact size for storage. Of course, most of the conventional foldable tables allow users to fold up their legs in order to make them more compact. There is nothing wrong with each individual foldable table. However, many organizations need lots of foldable tables for large-scale functions, storing a large number of them in another story. Typically, one may erect the folded foldable tables one by one and overlappedly lay them in order. One potential problem of this practice is that the foldable tables easily collapse. In order to prevent them from collapsing, some sort of strings or ropes may have to be used to tighten them. In other cases, one may wish to stack up all the foldable tables. However, the user may not be able to do so simply because the upper one may not be able to securely stack on the lower one.
Second, the foldable table may not be secure enough. In order that the foldable table to be portable, the material used for manufacturing the tabletop should be light in weigh, such as plastic. This can be easily justified by the fact that most of the conventional foldable tables have their tabletops made by come sort of plastic. However, light material probably suffers from inadequate strength, making the foldable table not secure enough, especially when it is loaded with fairly heavy objects. Though some manufacturers employ light but strong material, such as fiber reinforced composites, the foldable table made by this kind of material is unavoidably expensive which decreases the willingness of consumers to buy this product. One may choose to sacrifice the portability of the foldable table by making the tabletop with heavier and more rigid material. Nonetheless, portability and rigidity are mutually contending.
Besides, almost all conventional foldable tables have their respective tabletop supported at four corner portions, or at least separate supporting points along the edge portion of the tabletop. However, very often, an object will be placed at the middle portion of the tabletop. This creates a large bending moment to the tabletop and, if the tabletop was not strong enough, it would be broken or deflected after being used for a period of time. Also, with such kinds of mechanical designs, any loading loaded on the tabletop will not be evenly shared among the foldable table frame.